Much of what we know about our place in the natural world comes from the remains of those who came before us. Even small bone fragments from our hominin relatives can be used to reconstruct aspects of their lives, such what they ate, how they moved, and their positions in our family tree.

Other aspects, though, can never be fully understood, regardless of the amount of data that exists. Fossils are the only remaining traces of once-living beings, and their collective and individual lived experiences simply cannot be known. Yet, because the value in considering these aspects of humanity is philosophical rather than scientific, it is often overshadowed by scientific debates based on what we can actually interpret.

A few weeks ago, a new study of Australopithecus sediba—a nearly two-million-year-old hominin from South Africa first described in 2010—demonstrated that, despite its relatively modern morphology, it could not be the ancestor to our genus Homo, as a previous hypothesis had claimed. This led some to believe that this new interpretation effectively put A. sediba, now stripped of its ancestor status, “back in the ground.”

But do findings like these really invalidate the importance of this extraordinary discovery? In the second week of May 2018, I found myself inside of a bank vault filled with bones. After a 15-hour flight to get there, I was exhausted, anxious, and trying to quiet my shaking hands to avoid dropping anything. “The vault,” as it’s known colloquially, is a heavily protected room at the University of the Witwatersrand in Johannesburg, South Africa, filled with precious human fossils from the Cradle of Humankind World Heritage Site. I was finishing up the first year of my PhD in evolutionary anthropology in the United States, and what I saw in the vault caused my eyes to well up with tears.

In front of me were hundreds of bones that I had spent the last five years reading about and only dreamed of seeing. Inside a glass case was the Taung Child, the skull of an ancient human relative that had died 2.8 million years ago with the fossilized brain intact, considered one of the most important fossil finds of the 20th century. Another case, hidden behind a column in the center of the room, was covered in a bright red sheet—off-limits to scientists who weren’t part of the team that was still describing the skeleton within it 15 years after its discovery.

Two other glass cases contained the partial skeletons of A. sediba, which had been puzzling my PhD advisor regarding their antiquity and presence of modern traits. The rest of the room stretched before me with walls lined with drawers labeled with species and specimen numbers. I stared around me in awe until I heard my lab mate call my name.

Three years prior, I would have only seen data points. The first time I worked extensively with human bones, as an undergraduate working on my thesis on a pre-Columbian unclaimed Native American grave site, I tried hard to be academic and view them as specimens—pieces of data to be identified and measured. Yet, I couldn’t help but imagine what their lives had been like. Holding the bones of people I would never meet while seeing parts of these people that they themselves never saw was a surreal and stirring experience.

Now, as a second-year PhD student, I let these feelings flow through me, appreciating the unique intricacies of each human life and how, ultimately, we are all reduced to the same fate.

I was not prepared, however, for the feelings that washed over me when my lab mate carefully handed me one of the skulls in the vault. I was terrified. Why are they letting me touch this? I thought frantically. Shouldn’t I be wearing gloves? Can you get jail time for dropping a fossil? Surely I’d be kicked out of the program at least?

Slowly, this fear melted into a familiar awe. In my hands was the skull of a not-quite-human: a young male Australopithecus sediba. He had probably died when while he was walking above a cave chamber hidden underground, tripping into one of the exposed openings. He was alive before woolly mammoths existed, when 200-pound saber-toothed cats roamed the earth, and he lay where he died for nearly two million years while the rest of human history continued without him.

Did this human relative have thoughts or feelings? Did he feel pain or fear when he fell? Was his chimp-sized brain capable of generating happiness or sadness or anger? I looked into the hollow eye sockets and shivered, seeing at once both the deep past and inevitable future.

As paleoanthropologists, we aim to understand humanity in all its forms. Yet, we study ancient skeletons and build careers on debating their significance while ironically forgetting about the lives that these remnants represent—ancestor or not. We should take care to remember those facets of lives lost to history—the parts of humanity that will be forever beyond the grasp of science—and acknowledge that although data and interpretations may change, each piece of the puzzle has inherent value.